The present invention relates to transmission assemblies, particularly to a structurally improved transmission assembly which is applicable to be connected with an ornamentation or a doll for performing bilateral rotation to achieve their cosmetic effect, and the parts such as those precise yet breakable spindles used in the assembly will be prevented from damages during their manufacturing, packing or transportation.
Current transmission assemblies for rotatable toys are composed of a plurality of pinions and electro-magnetically actuated by a set of battery and circuit. Upon the engagement of the pinions in different gear ratio, the transmission assembly can provide reversible spins to an ornament as they are connected together. However, it presents at least the following disadvantages outlined as follows:
1. Most spindles of the pinions have their tapering pointed noses diametrically lesser than their bodies that are breakable in manufacturing or in packing,
2. Some of those pinions are composed of several parts in different material, such as a pinion is comprised of a metallic spindle, a plastic gear and a flat magnetic ring which causes a complicated manufacturing process and a difficult quality control for a producer,
3. Those sockets used to bear up the noses of those spindles in their casings are mostly inlaid with rubies in order to be durable and free from friction drag. But the rubies are found cracked under heavy pressure of the rotatable magnetic ring. Although some of the producers adapting frictionless metallic material instead of the rubies, they are failed because the metal is rusty and easily causes directional deviation during their assembling.
4. A brake block on the inner periphery of the casing which is made incorporated with a stopping rod on a main pinion to have that pinion to be reversibly rotated is made of hard material that unavoidably causes continuous tapping noise. Since the brake block is stably disposed on the inner periphery of the casing, once the stopping rod touches on, the on rotating pinion will return back immediately for another turn of bilateral rotation. Thus, each turn of such bilateral rotation can never exceed 360.degree.. The producer also adapts an elastic metallic plate instead of the stable brake block in order to provide adequate elasticity to eliminate the tapping noise and to have that each turn of the bilateral rotation of the main pinion can exceed 360.degree.. But all in vain because the metallic material is rusty and it brings up complications in manufacturing process. Another example is a plastic sleeve wrapped on the stable brake block which can eliminate the tapping noise, but it makes the extent of each turn of the reverse rotation more less. Besides, it consumes more manpower.